Macula, the impossible typeface by Fonthausen
Macula was originally designed for a design pitch for the graphic design organisation in Breda, the Netherlands. After the pitch, the typeface was expanded with a complete Latin characterset. Each character has a counterpart.
The family consists of four styles, each built with opentype features like contextual alternates (re-orders the characters and their counterpart), stylistic alternates and extended kerning and local language features.